The present invention relates to yarn packages as used in the textile industry and, more particularly, to yarn carrier structures upon which yarn is wound to form a yarn package.
In the textile industry, yarn is handled by winding a predetermined quantity of yarn upon a core structure to form a yarn package that can be readily transported, stored, processed, and mounted onto and demounted from yarn processing machines and handling equipment. To date, industry-wide dimensional and configuration standards have not evolved for yarn carrier structures. In general, the core or carrier structures are configured as a hollow cylinder or cone upon which the yarn is wound and fabricated from various types of plastics, wire mesh, or paper-like materials. While the exterior profile of the yarn carrier structure varies widely, yarn carriers all have some type of central opening that allows the yarn package to be placed onto and removed from shafts and `pins` used throughout the industry to mount yarn packages. Regardless of the particular yarn carrier configuration and the manner by which the yarn is wound upon the exterior of the carrier, it is important that the leading and trailing ends of the yarn package be accessible to the user to facilitate the mounting of the yarn package onto various machines and the feeding or threading of the yarn into the machine. For example, in the beaming of warp yarns, a large number of yarn packages are mounted on a creel with the yarn from each yarn package wound about the beam. Prior to the yarn from an `active` yarn package being exhausted, an attendant mounts a replacement yarn package adjacent the active package and knots or splices the trailing end of the active yarn package to the leading or beginning end of the replacement yarn package. When the active yarn is depleted, yarn will then be delivered from the replacement package which then functions as the active yarn package. This creeling procedure requires that the operator be able to reliably locate both the trailing end of the currently active yarn package and the leading end of the replacement yarn package to effect the desired knotting or splicing operation.
In a majority of textile environments, no formal means is provided to locate the leading end of the yarn its location being random on the outer surface of the yarn package. The trailing end of the yarn, normally referred to as the transfer tail, consists of a short segment of yarn that may or may not be wound around the base of the yarn package, aside of and apart from the main body of the yarn package.
Various techniques have been used to assist the operator in locating yarn ends. In more sophisticated arrangements, one end of the yarn carrier tube is provided with yarn receiving grooves, slots, or notches to assist in retaining the transfer tail in place. For example, in U.S. Pat. No. 1,924,510 to Parks, chordal slots are cut in an axial end face of the yarn tube with a portion of the transfer tail segment placed within the slots. Additionally, cutouts or relieved portions are provided in the end face of the yarn tube to allow an attendant to readily grasp the yarn end captured within the slot. In other arrangements, as represented in U.S. Pat. No. 4,005,567 to Mariani, a simple tab is provided on the circumferential surface of the yarn tube with a segment of the transfer tail wedged beneath the tab to secure the yarn end in place. In addition to securing the yarn end to the yarn tube, the yarn end has been retained in an auxiliary structure. As shown in U.S. Pat. No. 4,065,073 to Rohner, a wheeled yarn package cart is provided with a plurality of hollow, open-ended pins upon which the individual yarn packages are mounted. The pins are connected to a sub-ambient pressure source and function as suction tubes into which a yarn end is inserted and retained in place.
While conventional yarn package structures have been reasonably well-suited for the manipulation of yarn in the textile industry, considerable labor is required to load and unload the yarn packages throughout textile manufacturing processes with each package loading often requiring the finding and manipulation of the yarn ends. It would be advantageous to be able to eliminate this labor requirement by automation of these functions.
While progress has been made in lowering the labor content of many aspects of the textile manufacturing industry, the disparate nature of yarn carrier structures and yarn packages, as they have evolved, represent a formidable challenge to the automatic machine manipulation of yarn packages, particularly where the machine must also reliably locate the leading and trailing yarn ends of each yarn package.